Reset valve for train-control mechanism



Oct. 12 1926. 1,602,775

E. MURRAY ET AL I RESET VALVE FOR TRAIN CONTROl MECHANISM Filed Dec. 15. 19243" I ovmio'o E MOP/PH Y W 252 Mu/P/m y VWMW Patented Oct. 12, 1926.

UNITED STATES Lori-"ice. Y

.EARLE MURRAY AND WILLIAM B. MURRAY, OF DANiVILLE, ILLINOIS, ASSIGNORS TO THE MILLER TRAIN CONTROL CORPORATION, OF STAUNTON," VIRGINIA, A COR- "PORATION' or VIRGINIA.

RESET VALVE FOR TRAI -compel. mnonnms vr.

Application filed December 13 1924. SerialNo. 755,760.

This invention relates to train control mechanism, and more particularly to a posii tive stop valve adapted to be opened when the control mechanisn'i is actuated and prevent return of the vcontrol mechanism to its normal position until the stop valve is reset.

An object of theinvention is the provision oi an' attachment for train control systems anced to retain the .piston ina set position,

and means actuated by thetrack conditions are provided to unbalance the pressure, which attachment is connected to the said cylinder and is adapted to be actuated by the unbalancing of the pressure in the cylinderto open a valve and prevent a balanced pressure from being re-established in "the cylinder until the valve is closed.

More specifically, the invention comprises cylinder having a piston arranged therein, one end of the cylinder being connected to ,the'niain reservoir of the train system and the other endbeing connected to the main cylinder of the train control mechanism whereby a balanced pressure will normally exist in the re-set valve cylinder. The'cylinder is provided with an outlet port communicating withlthe atmosphere and having a valve therein adapted to be moved to an open position upon movement of the piston, and suitablemeans are provided for closing the valve either manually or through the provision of an electric circuit adapted to be established by closing a switch or by an automatic governorwhen the train comes to a stop.

In the accompanying drawings,'we have shown one embodiment of the invention. In this showing:

The figure is a diagrammatic side elevation of a train control system ofthe type shown in the copending application of 'William B. Murray, filed April 21, 1922,"

Serial No. 555,854, showing the re setvalve connected thereto.

Reterrmg to the drawings, thereterence numeral l' designates the casing of an en Y chain.

A valvepasing 20 is arranged adjacent the main cyl nder. This casing 1s provided with gineers air brake valve of the usual construction which is mounted in the vehlcle at any conven ent po nt,'generally 1n the engineers cab. A shaft (not shown) extends through this casing and is provided with a lever"2 topermit revolution of the shaft to open or close the valve andapply the brakes.

The control apparatus consistsjot a cylinder 3 which is closed atits lower end and is pro vided with a port a communicating (with thetop of the cylinder to admit air or other 7 fluid under pressure. IThis port is connected to a source of fluid under pressure, such as the air reservoir, by means of a pipe 5. The upper end of the cylinder is closed by a head 6, which proyidedwith a central boss 7. A piston 8 is arran 'ed in the cylinder and this piston is provi ed with a piston rod 9 extending thro ngh the boss 7 The piston rod isadapted to be surrounded by suitable packing retained imposition by means of a pecking gland 10. The inner end of the boss "is surrounded by a suitable strip ofpacking 11. A casing 12 surrounds the piston rod and this easing carries a -bracket 18 adapted to support a steel roller 14 mounted on a pin15. A 'cl1ain16, preferably of steel,

is connected to the upper end of the piston rod. The chain maybe connected to the piston rod in any suitable manner. A drum 17 "is secured to the shjaft of the air brake Valve and thejothere nd of the chain is secured to jtliisj idruinf The drum is'provided with a depend ng lug or pin 18, shown in dotted "line'sfwhich ,is adapted to engage one side of the air. brake lever to limit the revolution ofthe drum A cover plate 19 is connected to the casin 12 and extends over the .drum and the horizontal "portion of the a main "inlet port 21 communicating with a passage in the cylinder wall extending tothebotton ot the cylinder. The piston is provided with a restricted passage 23 "whereby the lower portionot the cylinder .necting the inlet ,passage to a chamber26. Thebottom offthephamber is closed. by a plate 27. This plate is provided with an opening having a valve seat formed on its upper end. A chamber 28 is arranged below the plate and the side wall of the chamher is provided with an opening adapted to receive a whistle 29. A valve member 30 is arranged in the chamber 26 and is provided with a valve 31 adapted to engage the valve seat 24. The lower portion of the valve member is also provided with a valve adapted to engage the seat formed in the opening in the plate 27. The valve member is provided with a stem 32 extending into the chamber 28. The main valve 31 is normally in open position as shown, and is adapted to be controlled by a magnet 33. As shown, this magnet is provided with a core 3-1 which is raised when the magnet is energized. A pin 35 is arranged above the core and is adapted to be lifted by the core to raise the valve member 30.

The upper end of the valve casing is provided with a port 36, communicating with the top of the cylinder. The valve casing is closed by a cap 37, the interior of which is hollow, forming an auxiliary chamber 38. This chamber is provided with an outlet opening 39, communicating with a passage d0. The main valve chamber-26 is provided with an outlet 41, communicating with a conduit-42. The passage 4L0 communicates with the conduit through the passage ll. The passage 37 is provided with a valve seat normally engaged by a valve 43. This valve is provided with a depending stem 44, which projects into the inlet passage 25 and is adapted to be engaged by the main valve when the main valve is raised.

The conduit 42 communicates with a shoe 45 arranged on the locomotive or tender at any convenient point and adapted to enramps arranged at spaced intervals along the track. The shoe is mounted in a bracket 46, secured to a part of the vehicle and arranged relatively close to the ground. As shown, the shoe comprises a substantially cylindrical member 47 having flanges a8 formed on opposite sides. These flanges are provided with slots 49 to permit vertical adjustment of the shoe in assembling. Bolts 50 pass through these slots and are received in suitable openings in the bracket. The shoe is insulated from the bracket to insulate it from the vehicle. A

piston 51 is arranged within the cylinder,

57 on its lower end which forms the contact member of the shoe. The shoe is connected to the magnet by means of a lead wire 58.

The reset valve consists of a cylindrical casing 59 mounted on a locomotive at any C(silYCDlGllt point and communicating with the main reservoir by means of a pipe 60. is shown, the pipe 60 is connected to pipe 5 by a coupling 61. The lower end of the casing is provided with a port 62 connected to a pipe 63 communicating with the main cylinder 3 of the control apparatus. A piston 6% is arranged in the cylinder and this piston is provided with a passage 65 whereby a balanced pressure will normally exist in the cylinder. The top of the cylinder is closed by a plug 66 having a central pcning through which the piston rod 67 extends. A sheet of packing 68 is arranged around the lower end of this opening. The lower portion of the valve casing is provided with a chamber 69, communicating with the main cylinder through a restricted passage. This passage is provided with a valve seat adapted to be closed by a valve T0 having a stem 71 projecting upwardly to a point adjacent the piston. A spring 72 normally retains the valve in closed position. The chamber 69 is provided with a passage 78 communicating with an outlet port 74. The passage 72 is provided with a valve seat 75 adapted to be engaged by a valve 76. A magnet 77 is arranged beneath the valve 76 and this magnet is provided with a core 78 adapted to be raised when the magnet is energized. As shown, the core is provided with an extension 79, projecting from the bottom end of the casing to permit manual operation of the valve 76. The magnet 77 is connected to a local circuit consisting of a source of current 80 in which a push button or hand operated switch 81 may be arranged. As shown, a lead wire 82 extends from the source of current through the switch 81 to one side of the magnet and a lead wire 83 extends from the other side of the magnet back to the source oi. current. A governor Set may be arranged therein to prevent the circuit from being closed except when the vehicle is stopped. The operation of the main control apparatus is substantially the same as that described in the prior patent to lVilliam B. Murray, heretofore referred to. Normally, the pressure on each side of the piston 8 is equal and the parts remain in the position shown in the drawings. At each ramp, the shoe is lifted and the air in the conduit {1:2 is exhausted. It the valve 31 is in open position, the fluid is exhausted from the bottom oil. the cylinder. However, when the train approaches a clear block, the ramp is energized and current is fed through the shoe to the magnet by the wire 58 raising the valve 31 and preventing the air from being exhausted from the cylinder. At the same time, the auxiliary valve 43 is raised to permit air to pass through the passage 36 and the passage 40 to replenish the supply exhausted from the conduit 42. When a dead ramp is encountered, the valve 31 remains in an open position and the piston 8 moves downwardly in the cylinder, due to the pressure of air on its upper surface, re-

volving the drum 17 and thus turning the engineers air brake lever to apply the brakes.

The re-set valve is adapted to be actuated whenever the air in the lower portion of the main cylinder is exhausted. Normally, the pressure is equalized in the re-set valve cylinder 59 due to the fact that the upper end of the cylinder is in communication with the main reservoir through the pipes 5 and 60 and the lower end is in communication with the bottom of the main cylinder through the pipe. 63. The portin the piston permits the pressure to equalize. The valve is normally retained in closed position by the spring 72 and the passage 74 is thus disconnected from the pipe 63. When the pressure falls in the cylinder 3, the pressure in the lower portion of the re-set valve cylinder is decreased and the pressure on the upper surface of the piston 64 moves it downwardly, causing the lower face of the piston to engage the valve stem 71, thus opening the valve 70. lVhen the valve 70 is open, the bottom of the cylinder 3 is in communication with the atmosphere through the pipe 63, the valve cylinder 59, chamber 69, passage 73 and port 74. As long as this valve remains in an open position, the brakes will be held in an applied position regardless of the position of the valve 31, and even after the ramp has been passed, the engineer is unable to proceed until the re-set valve has been set. The re-set valve casing may be arranged outside the engineers cab, if desired, in order to compel him to leave the cab to reset the valve. If the re-set valve is to be manually operated, the core 7 8 is moved upwardly by .forcing the extension 79 upwardly, raising the valve 76 to its seat. This closes the port 74 and the pressure immediately begins to build up in the bottom of the main cylinder 3 and in the bottom of the re-set valve cylinder. As soon as the pressure is equalized, the pistons 8 and 64 are raised and the valve 70 closed by the spring 72.

The manually controlled switch 81 can also be employed to set the reset valve. By closing the switch, the magnet 78 is energized, raising the core in the manner just described to close the valve 76. When the speed governor 84 is connected to the circuit, it is adapted to break the circuit when the governor is moving and permits the local circuit through the reset magnet to be closed only when the vehicle is in a state of rest or at some predetermined speed.

It is to be understood that the form of our invention herewith shown and described is to be taken as a preferred example of the same, and that various changes in the shape, size, and arrangement of parts may be resorted to without departing from the spirit of the invention or the scope of the subjoined claims.

We claim:

1. In a device of the character described, a casing, a movable member mounted in said casing and operatively connected to a part of the vehicle control mechanism, means for maintaining a balanced pressure in said casing, means controlled by the movement of the vehicle to release the pressure in one end of said casing, and a valve adapted to be opened by the release of pressure in one end of said casing and prevent re-establishment of a balanced pressure in said casing while said valve is in open position.

2. A device constructed in accordance with claim 1 wherein means are provided for independently closing said valve.

3. A device constructed in accordance with claim 1 wherein means are provided for independentlyv closing said valve, said means being inoperative when the vehicle is moving faster than a predetermined speed.

4. In a device of the character described, a casing, a movable member mounted in said casing and operatively connected to a part of the control mechanism of the vehicle, means for maintaining a balanced pressure in said casing, means controlled by the movement of the vehicle to release the pressure in one end of said casing, an auxiliary casing connected to the said end of said casing, the other end of said auxiliary casing being connected to the main air reservoir to maintain a balanced pressure therein, a piston mounted in said auxiliary casing, one end of said casing being provided with an outlet, and a Valve arranged in said outlet and adapted to be opened by the movement or said piston.

5. A device constructed in accordance with claim 4, wherein said valve is normally maintained in closed position by a spring and said spring is compressed when said valve is opened by said piston.

6. A device constructed in accordance with claim 4 wherein a magnet is arranged adjacent said valve and said magnet is provided with a core adapted to engage said valve when said magnet is energized to move said valve to a closed position.

In testimony whereof, we aflix our signatures.

EARLE MURRAY. WILLIAM B. MURRAY. 

